1. Field of the Invention
This invention generally relates to a bicycle shift controller. More specifically, the present invention relates to a bicycle shift controller two independently operable levers.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle shift controller.
With respect to the actual shifting operation, bicycle shift controllers can be divided into at least two groups. A first kind of bicycle shift controller has a lever rotatably coupled to the base member for rotating the cable take up member into a plurality of positions, whereby each position represents a respective gear. Thus for a shift controller that is to shift the bicycle's gear transmission between a plurality of different gears, the cable take up member has a first position for the first gear, a second position for a second gear and a “n” th position for a “n”th gear. The lever also has a first position for the first gear, a second position for the second gear and a “n”th position for the “n”th gear. Shifting between the respective gears thus occurs by shifting the lever from one position to another position, whereby the lever remains in that other position once shifting has been completed. This kind of bicycle shift controller is disclosed in U.S. Pat. No. 5,186,071 (Assigned to Maeda Industries, Ltd.).
Another type of bicycle shift controller is the type of controller applicable to the invention described below. Here, one lever is used for rotating the cable take up member in a cable-release direction, whereby another lever is used for rotating the cable take up member in a cable-winding direction. At least one of the levers is designed in such a manner that it has a rest position and a shift position, whereby the lever preferably returns automatically to the rest position once the shifting has been completed. This second type of bicycle shift controller with the lever automatically returning to the rest position provides the advantage that the lever will always rest in the rest position and thus always be in the same relative position to the handlebar before the shifting action takes place. This allows the user to get used to a relative position of the lever with respect to the handlebar. If the user wants to initiate the shifting process, he will always find the lever in the same position, which is considered as more comfortable.
Using one lever for rotating the cable take up member in a cable-release direction and another lever for rotating the cable take up member in a cable-winding direction further has the advantage that the user can get used to using the one lever to increase the gearing and use the other to decrease the gearing. This also makes use of this type of bicycle shift controller more comfortable.
A bicycle shift controller is disclosed in U.S. Pat. No. 5,601,001. This patent realizes the advantages of having a lever with a rest position and a shift position, but does not realize the advantages of assigning the cable-release direction to one lever while assigning the cable-winding direction to another lever. Here, a base member mountable to a handlebar via a lever bracket that also pivotally supports a brake lever is provided. A cable take up member is rotatably coupled to the base member for pulling and releasing a control cable. A single lever is rotatably coupled to the base member about a rotational axis for rotating the cable take up member, the lever having a rest position and a first shift position (“up”-position) and a second shift position (“down”-position). The single lever is designed with the shape of the letter Y, whereby the base portion of the lever is rotatably coupled to the base member for rotating the cable take up member and whereby the first arm points forward with respect to the bicycle traveling direction when the bicycle shift controller is attached to the handlebar for normal usage and whereby the second arm points backwards. The forward pointing first arm of the Y-shaped lever has an operating surface designed on the forward facing part of said forward pointing arm. The second, backward pointing arm also has an operating surface, this operating surface, however, being designed on the backward facing side of this second, backward facing arm of the lever. The forward facing operating surface is situated and provided for allowing the user to comfortably pull the single lever backwards in what is called “down” direction for shifting the gearing of the bicycle transmission downward. The second, backward facing operating surface is designed and provided for allowing the user to comfortably push the lever in the forward direction (called “up” direction). Though allowing for comfortable and easy-to-learn shifting, because for each of the respective shifting actions (upward-shifting, downward-shifting) the user can refer to the same sequence of movements, use of the bicycle shift controller is limited to this type of movements.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved bicycle shift controller. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.